In the experiment Al-Zr(CO3)2 components were utilized to in situ synthesize the Al2O3, Al3Zr reinforced aluminum matrix composites. Low frequency and high frequency electromagnetic fields were combined and introduced into the fabrication of particulates reinforced aluminum matrix composites. The average size of particulate and grain size of matrix were refined to 0.5~1μm and 20~40μm separately. The particulates distributed uniformly in matrix. The Lorenz force improved the kinetic condition and accelerated the nucleation of endogenetic particulates. At the meniscus of solidifying billet the high frequency electromagnetic field was applied. The surface quality of billet was enhanced obviously.